With a history that can be traced back to 1660 the Household Cavalry is the most senior component of the British Army. The National Archives has now made service records, from 1799 to 1920, for over 12,000 servicemen from the Household Cavalry available online to view and download.
According to TNA information the records are from series WO 400 and include those serving during the Battle of Waterloo, the Boer War and the First World War.
Information is from the original handwritten enrolment forms, conduct, casualty, medical and pension documents.
19 men by name Reid, five with first name John, include those serving with the Royal Horse Guards and the First and Second Life Guards. Search from the form at http://www.nationalarchives.gov.uk/records/household-cavalry-soldiers.htm. The cost to view images of the original is £3.30.